example pom to package one jar including pre-supplied jar-dependencies - uses https://gist.github.com/hotzen/2da60295a410589078086b7f06af3fee

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>VENDOR</groupId>
    <artifactId>foobar</artifactId>
    <version>3.6</version>
    <name>FOOBAR</name>

    <properties>
        <skipTests>true</skipTests>
    </properties>

    <dependencies>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>activation</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/activation-1.1.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>bcpkix-bouncycastle</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/bcpkix-bouncycastle-1.68.s3.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>bcprov-bouncycastle</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/bcprov-bouncycastle-1.68.s3.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>foobar</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/foobar.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>commons-codec</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/commons-codec-1.15.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>commons-collections</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/commons-collections4-4.4.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>commons-compress</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/commons-compress-1.20.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>commons-io</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/commons-io-1.3.1.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/commons-logging-1.2.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>commons-math</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/commons-math3-3.6.1.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>fontbox</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/fontbox-2.0.24.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>javax-mail</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/javax.mail-1.6.2.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>jfxrt</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/jfxrt-8.0.999.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>logapi</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/LogAPI.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>pdfbox</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/pdfbox-2.0.24.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>poi</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/poi-5.0.0.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/poi-ooxml-5.0.0.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>poi-ooxml-lite</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/poi-ooxml-lite-5.0.0.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>rhino</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/rhino-1.7R4.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>sparsebitset</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/SparseBitSet-1.2.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>tyrus</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/tyrus-standalone-client-1.15.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>xmlapis</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/xml-apis-1.4.01.jar</systemPath>
        </dependency>
        <dependency>
            <groupId>VENDOR.jars</groupId>
            <artifactId>xmlbeans</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>system</scope>
            <systemPath>${basedir}/lib/xmlbeans-4.0.0.jar</systemPath>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>3.2.0</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>single</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <appendAssemblyId>false</appendAssemblyId>
                    <descriptors>
                        <descriptor>${basedir}/assembly.xml</descriptor>
                    </descriptors>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-deploy-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <distributionManagement>
        <repository>
            <id>the-repo</id>
            <url>https://repo/</url>
        </repository>
    </distributionManagement>
</project>